A freshman taking a Dying Environment class believes that blood is a substance; however, he or she is incorrect. Substances and mixtures are both types of matter that act in different ways. A mixture is a combination of two or more substances that are not combined chemically. Furthermore, substances cannot be separated by physical means, whereas mixtures can. Because it contains many substances that can be separated through physical means after being combined, blood is a mixture instead of a substance. Blood has different components, or substances, that make it a mixture: red and white blood cells, platelets, and plasma. These different parts compose blood in a uniform way, but they can be physically separated from each other after being
